基于MEMS加速度计与磁力计的位移计设计

Displacement Meter Design Based on MEMS Accelerometer and Magnetometer

基坑水平位移监测是基坑安全的重要检测项目之一。针对现有的阵列式位移计在基坑水平位移监测中容易产生扭转误差的问题,设计了一种基于MEMS加速度计与磁力计的位移计,能够同时满足基坑水平位移与沉降位移监测的需求。介绍了位移计自动化实时监测系统组成。对位移计的结构以及监测节的硬件电路进行了设计,并制作完成了位移计样机。阐述了位移计通过对加速度计与磁力计的数据进行融合,计算位移坐标的测量原理和扭转误差校正的方法。最后通过模拟监测节间发生扭转时位移计水平位移监测的实验,以及位移计沉降位移监测试验。实验结果表明,该位移计能够精确测量水平与沉降位移,并能够有效校正位移计竖直安装时监测节扭转带来的扭转误差。

The horizontal displacement monitoring of foundation pit is one of the important testing items of foundation pit safety.In view of the problem that the existing array displacement meter is easy to produce torsional error in the monitoring of horizontal displacement of foundation pit,a displacement meter based on MEMS accelerometer and magnetometer is designed,which can meet the requirements of monitoring horizontal displacement and settlement displacement of foundation pit at the same time.The composition of automatic real-time monitoring system of displacement meter is introduced.The structure of the displacement meter and the hardware circuit of the monitoring section are designed,and the prototype of the displacement meter is made.The measuring principle of displacement coordinate calculation and the method of torsion error correction by integrating the data of accelerometer and magnetometer are described.Finally,the horizontal displacement monitoring experiment of the displacement meter and the subsidence displacement monitoring experiment of the displacement meter are simulated to monitor the torsion between nodes.The experimental results show that the displacement meter can accurately measure the horizontal displacement and settlement displacement.The device also can effectively correct the torsion error caused by the monitoring joint torsion when the displacement meter is installed vertically.